In my commonly-assigned copending application Ser. No. 10/721,921 filed 10 Dec. 2003 and corresponding to German application DE 102 58 101 and the corresponding patent DE 102 58 101 B1, a contact spring is described for an antenna unit adapted to be mounted upon a vehicle body in which a carrier or support plate receives at least one contact spring and the antenna amplifier bears against a bent portion of the contact spring forming one contact surface. In the system of DE 102 58 101, the carrier plate is provided between a window pane of the vehicle body which may have contact locations connected with an antenna applied to that window pane and an electronic device which can be an antenna amplifier or the housing thereof.
The support plate has a cutout in which a contact spring is arranged with a particular configuration, for example, the shape of a loop having inwardly bent ends and a bight between those ends. The two ends can be pressed together in mounting the contact spring in the support plate so that they overlap, i.e. one of the bent ends is a gauge in the other. The advantage of this configuration is that the contact spring is trapped on the support plate and can be easily mounted thereon, can have the requisite resilience in mounting the antenna amplifier on the vehicle window pane, and can provide a problem-free reliable and convenient electrical contact between the electronic device and the antenna. While this construction has proved to be successful in practice, it does have a drawback in that it is difficult to mount the contact spring on the support plate automatically and thus to automate the formation of the contact arrangement. It has been found to be necessary to utilize manual assembly techniques. Another drawback is that the precision of the position of the contact spring leaves something to be desired since the contact spring can move with considerable latitude around the rib about which the contact spring fits.